1. Field of the Invention
The invention relates to a lance and a method for the determination of reaction data of a reaction sequence, in which a reaction gas is top-blown by means of at least one lance onto a metallic melt in a metallurgical vessel and simultaneously measured data are recorded, as a function of which reaction data about the reaction sequence are determined, wherein the lance for the recording of measured data blows out a gas being conveyed separately from the reaction gas via at least one outlet opening of at least one measuring line.
2. Description of the Related Art
In order to be able to monitor or control a reaction sequence of a top-blowing process or oxygen-top-blowing process, it is known from the prior art (DE 1290557 A1) to measure the electrical conductivity between the lance and the metallurgical vessel during the reaction sequence. By means of these recorded measured data, the reaction sequence is interpreted or reaction data about the reaction sequence are determined therewith. In particular, supposedly overfoaming of the foamed slag, which is formed during the top-blowing of oxygen at a high flow velocity onto the melt in the metallurgical vessel, is also detected therewith and subsequently the danger of a slopping is reduced. However, the measured electrical conductivity is dependent on a large number of reaction parameters of the reaction sequence, and so the danger of an overfoaming can be detected only poorly reliably by means of such methods. Furthermore, metallurgical changes in the reaction sequence are manifested relatively sluggishly in the electrical conductivity, thus making a dynamic determination of reaction data about the reaction sequence difficult.
Moreover, a method for the determination of the depth of immersion of a lance in a metallic melt is known from DE 2239216 A1. For this purpose, a pressurized gas being conveyed separately from the reaction gas of the lance is blown out at the bottom end of the lance via a measuring line of the lance. Measured data about the pressure differences between an ambient pressure and the pressure at the bottom end of the lance are used for the determination of the depth of immersion of the lance. Disadvantageously, extremely violent chemical reactions of the reaction gas with the melt can be expected during the measurement, which falsifies the recording of measured data and thus may jeopardize the stability of the process.
In addition, for the measurement of the height of a foamed slag in a metallurgical vessel, it is known (U.S. Pat. No. 4,359,211 B) to inject pressurized gas through the wall of the metallurgical vessel at different heights. Such a measuring device needs a relatively complex structural change of the metallurgical vessel in order to be able to assure its leak-tightness at all times against escape of metallurgical melt despite wall openings.